/Engine/Source/Editor/SubobjectDataInterface/Public/SubobjectDataSubsystem.h
Add the given subobject to a new owner. This will remove the subobject from its previous owner if necessary.
true if the child was added successfully
bool AttachSubobject ( const [FSubobjectDataHandle](API\Editor\SubobjectDataInterface\FSubobjectDataHandle) & OwnerHandle, const [FSubobjectDataHandle](API\Editor\SubobjectDataInterface\FSubobjectDataHandle) & ChildToAddHandle )